‘Turning Off’ Genes, and HIV

A form of ribonucleic acid developed by researchers at the Massachusetts Institute of Technology silences genes that play a role in HIV infection, potentially showing a new way to combat the virus that causes AIDS.

The team used short forms of RNA that “turn off” genes vital for the production of proteins used by the virus to enter and infect cells. RNA carries the blueprint for constructing proteins.

“If many obstacles can be surmounted, this could be a basis for intervention in HIV treatment,” said Dr. Phillip A. Sharp, who led the research.

The work was conducted in the laboratory, and problems to be solved include finding ways to deliver the RNA to cells in animals or humans, to ensure it would not interfere with normal biological processes and would not have side effects, he said.

The work, reported Sunday in the online edition of the journal Nature Medicine, is a “proof of concept,” Sharp said. He won the 1993 Nobel Prize for the discovery of “split genes,” which changed how scientists look at evolution and advanced research into hereditary diseases, including some cancers.

Dr. Louis M. Mansky of Ohio State University, who was not part of the research team, said the findings were interesting, but added that “there are a lot of concerns as to how it would be applicable.”

Mansky said there have been difficulties in getting similar strategies to work in clinical settings.

In lab tests, the RNA reduced, but did not eliminate, the virus, and thus Mansky said it might be useful in addition to the current drugs used to combat AIDS.

But, he added, “I don’t think this, by itself, would be superior to the drug ‘cocktails’ now used for treating HIV individuals.”

RNA is present in most cells, carrying genetic information and operating in protein production.

The team currently is working with mouse genes, Sharp said.